FOREST PROTECTION 75 



capable of increasing alarmingly in numbers, owing to the short 

 gestation period of the females and the quantity produced at a 

 birth. Their attacks have frequently amounted to a scourge. 



The water-vole (Arvicola amphiblus]^ or water-rat, as it is 

 commonly but erroneously called, considered individually, is 

 the most injurious of the voles. It forms branching galleries 

 in the soil and bites through the thickest roots of trees. 

 Fortunately, it is of somewhat solitary habits. 



As a preventive measure against mice, the keeping down of 

 grass by maintaining a full crop of trees up to the time of re- 

 generation is recommended. When possible, seed should be 

 sown in spring rather than in autumn. Drain tiles, with 

 poisoned baits, may be placed about ; the drain tile pre- 

 vents larger animals from reaching the poison, and a piece of 

 celery hollowed to contain phosphorus answers well as bait. 

 Gamekeepers, by destroying owls, kestrels, weasels, and 

 stoats, greatly favour the numerical increase of mice and voles. 



BIRDS are troublesome chiefly in the forest nursery, where 

 the finches, sparrows, and other small birds attack seed and 

 the cotyledons, or first leaves, of germinated seed. Protection 

 is given by mixing the seed with one-tenth part by weight of 

 red lead, or by placing a framework such as that shown in 

 Fig. 5 (p. 45) over the seed-bed. 



Black game (Tetrao tetrix] occasion some damage by 

 nipping out the buds, preferring Birch and Scots Pine. 



Crossbills (Loxia sp.) attack the cones of Scots Pine and 

 Spruce, and eat the seeds. 



Woodpeckers (Picus sp.), especially the green species, do 

 a certain amount of damage. 



Most birds, by destroying insects, are much more useful 

 than injurious. 



Protection Against Forest Insects 



In the insect world the forest has many enemies, some of 

 which do a great deal of harm. Only in comparatively few 

 cases are effectual remedies available. Among the most 

 dangerous insect pests are the following : 



